A bill that seeks a referendum to ban adoption by same-sex couples and singles passed through Colombia’s Senate on last Tuesday.

The legislation, which would allow only heterosexual couples to adopt, is being spearheaded by Senator Viviane Morales (Liberal Party), who said that it “is opening a space for Colombians to pronounce on the fundamental values and principles of the family as the fundamental nucleus of society,” she told W Radio.

Just a year ago, Colombia’s Constitutional Court lifted a restriction on adoptions by same-sex couples.

The measure was celebrated at the time by the LGBT community in the country, but condemned by other sectors such as the church and conservative members of Congress.

In early 2016, Senator Morales led a campaign called ‘Sign for Mom and Dad’ which resulted in a petition signed by over 2 million Colombians to appeal the court’s ruling.

“This session of the Senate will be remembered as one of its most shameful in history,” said Senator Claudia Lopez, of the Green Alliance party, who has stood in strong opposition to Morales’ efforts.

President Juan Manuel Santos also stated his opposition to the proposed adoption ban during a radio interview in Spain on Wednesday.

“I am not in favor of that position. We are a government that has promoted the rights of all Colombians, including homosexual minorities,” he said.

The referendum bill now moves on to the House of Representatives, and ultimately requires the approval of the president and the Constitutional Court to go into effect.